Injection system



Jain. 14, 1947. D. E. MEITZLER 2,414,267

INJECTION SYSTEM Filed Jan. 28. 1944 3 Sheets-Sheet 1 V INVENTOR ATTORNEY 'INJECTION SYSTEM Filed Jan. 28, 1944 3 Sheets-Sheet 2 INVE NTOR he. 2 ,y g 7% maww ATTORNEY Jan. 14, 1947.

D. E. MEITZLER INJECTION SYSTEM J QJAMW.

ATTQRNKY v engaging shoes 32 on a thrust cup .34.

Patented Jan. 14, 1 9 47 srres PATENT OFFICE 2.414.267 mmcrron SYSTEM Donald E. Meitzler, Manchester, Com-1., asslgnor to United Aircraft Corporation, East Hartford, Conn, a corporation of Delaware Application January 28, 1944, Serial No. 520,069

12 Claims.

7 which, during the injection stroke of the plunger, is subject 'to a heavy end thrust, must be held in place by a thrust ring. A feature of this invention is the use of rocking shoe bearings between the sleeve and the thrust ring, thereby permitting heavier loads without hearing failure.

Another feature of the invention is the use of a number of rocking shoe bearings arranged for simultaneous engagement with the helix, to transmit the high loads developed during the reciprocation of the injection plunger.

Other objects and advantages will be apparent from the specification and claims and from the accompanying drawings which illustrate an embodiment oi the invention.

Fig. 1 is a sectional view through the injection device.

Fig. 2 is a perspective view of the thrust cup with the rocking shoe hearings in position, the :up being inverted. l i

Fig. 3 is a perspective view of the thrust ring with the rocking shoe bearings in position.

The injection device it is supported within a tubular bracket 82 which may be integral with a part of the wall of an engine cylinder it. The injection device is actuated by a rod it in the form of a reciprocating rack. The rack engages a pinion it which is supported in a hous ng 26 forming part of the injection device. The pinion is integral with a sleeve 22 journaled in the housing and supported by a bearing ring 23. A radial flange 26 on the sleeve is held between the end of bearing'ring 2t and a thrust ring 28 to prevent endwise movement of the pinion.

The inner surface of sleeve 22 has a helix 30 This is positioned over a casing 36 in which an injection plunger 38 is slidable. A coil spring 40 urges cup 34 axially to hold the shoes in contact with the helix. As-pinion i8 is reciprocated by rack l6, plunger 38 is moved axially in its-bore l2, theend of the plunger being held against cup 34 by a coil spring 44.

The injection system may be the accumulator type. Casing 36 may have opposed accumulator chambers 46 and, interconnected by a passage Fuel which. enters the end of bore 42 through an inlet port is pumped into the chambers through a groove 52 in an accumulator valve 54 which slides in a bore 56 in a ring 58 in casing 38. Fuel discharges from the accumulator chambers through a passage 60 and past a check valve 62 to the nozzle 64. The accumulator valve 58 moves endwise to engage a seat 66 at the end ofv passage 60 during filling of the accumulator chambers, being held on this seat by pressure of fuel on the other end of the valve. Injection occurs when a groove 68 in plunger 38 uncovers a vent port 10. This groove is connected to the end of the plunger 38 by a passage 12 in the plunger and causes a drop in pressure in here 42 when port 'lll is uncovered. This drop in pressure causes valve 54 to move against a seat 14 in the ring 58 in casing 36, closing groove 52 and opening passage for injection of fuel from the chambers. This injection device is fully described in the copending Meitzler application, Serial No. 486,625, above mentioned.

The bearing shoes 32 which engage helix 30 are in the form of rocking shoes mounted to rock on pins 16 extending from thrust cup 34 and arranged in a helix around the cup so that the the helix simultaneously. Each rocking shoe, as shown in Fig. 2, may be constructed so that the leading edge, during the injection stroke, is farther from the line of thrust through the center of oscillation than is the trailing edge. In this way, the bearing shoe, in moving On the helix, will develop a force on the shoe to move it into a position to provide the most effective wedgeshane lubricating film during the injection stroke of the plunger. Each shoe, during the retraction of the plunger, may rock to provide a wedgeshaped film of oil for effective lubrication on the return stroke. The bearing is long enough to assure the desired tipp ng of the shoe for providing the proper wedge angle.

To enable the thrust ring 28 to carry the heavy end thrust on the sleeve 22 during the injection stroke, this ring has a number of circular recesses 18, Fig. 3, extending radially to receive cylindrical bearing elements forming rocking bearing shoes having flat surfaces 82 engaging with the radial flange 26. Since bearing elements 80 are cylindrical, each element is adapted to rock in the thrust ring to permit the bearing surduring movement between this flange 2B and the bearing surface. Each element 80 will be large enough to provide a bearing surface 82 to assure the desired tipping of the shoe for providing the proper wedge angle. v

It is to be understood that the invention is not limited to the specific embodiment herein iling said member in position, one or said bearing means including a set of rocking shoes engagin said member.

7. An injection pump including a plunger, a :asing in which the plunger reciprocates, an oscillating member surrounding the plunger, means interconnecting said member and plunger for lustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims.

I claim:

1. An injection pump including a plunger, a casing in which the plunger reciprocates. an oscillating member surrounding the plunger, means interconnecting the member and plunger for causing reciprocation of the plunger in response to oscillation of the member, and bearing means in the form of rocking shoes forming a part of the interconnecting means between said member and the plunger.

2. An injection pump including a plunger, a casing in which the plunger reciprocates, an oscillating member having its axi parallel to the plungenmeans interconnecting said member and plunger for causing reciprocation of the plunger in response to oscillation of the member, and bearing means in the form of rocking shoes forming a part of the interconnecting means between said member and the plunger. f

3. An injection pump including a plunger, a

casing in which the plunger reciprocates, an oscillating member surrounding the plunger, means interconnecting said member and plunger for causing reciprocation of the plunger in response to oscillation of the member, and havinga cam thereon, said member bearing means in the form oi. rocking shoes forming a part of said means and engaging said cam.

4. An injection pump including a plunger, a casing in which the plunger reciprocates, an oscillatng member surrounding the plunger, means interconnecting said member and plunger for causing reciprocation or the plunger in response to oscillation of the member, and bearing means in the form of rocking shoes forming a part of said interconnecting means.

5. An injection pump including a plunger, a casing in which the plunger reciprocates, an 05- cillating member surrounding the plunger; means interconnecting said member and plunger for causing reciprocation of the plunger in response to oscillation of the member, bearing means forming a part of the interconnection between said member and plunger, and bearing means for holding said member in position, one of said bearing means including a rocking shoe.

.6. An injection pump including a plunger, a

casing in which the plunger reciprocates, as oscillating member surrounding the plunger, means interconnecting said member and plunger for causing reciprocation of the plunger in response to oscillation of the member, bearing means forming a part of the interconnection between said member and plunger, and bearing means for holdcausing reciprocation ofthe plunger in response to oscillation of the'member, bearing means form- I ing a part of the interconnection between said member and plunger, and bearing means for holding said member in position, each of said bearing means including a set of bearing shoes engaging said member. 7

8. An injection pump including a plunger, a casing in which the plunger reciprocates, an oscillating member surroundin and causing recip-.

rocation of the plunger, and having a helix thereon, "a" thrust cup surrounding and engaging the plunger, and a set of rocking shoes arranged in a helix on the cup and engaging the helix on the oscillating member. 1

9. An injection pump including a plunger, a

cillating member surrounding the plunger; means connecting said member and plunger and causing reciprocation of said plunger in response to oscillation of said member, and bearing means in the form of rocking shoes for holding the member in position.

11. An injection pump including a plunger, a casing in which the plunger reciprocates, an oscillating member surrounding the plunger, means connecting said member and plunger and causing reciprocation of said plunger in response to oscillation of said member, a housing in which the member is positioned, a thrust ring in the. housing for holding the member in position, and a number of rocking shoes between the ring and member andforming a bearing.

12. An injection pump including a plunger, a casing .in which the plunger reciprocates, an oscillating member surrounding the plunger,'means connecting said member and plunger and causing reciprocation of said plunger in response to oscillation of said member, a housing in which the member is positioned, a thrust ring in the housing for holding the member in position, and a number of rocking shoes between the ring-and member, said shoes fitting in radially extending recesse'sin the ring.

DONALD E. MEITZLER.

Certificate of Correction Patent No. 2,414,267. January 14, 1947. DONALD E. MEITZLER It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 3, line 35, claim 3, for and having read said member having; line 36, same claim, for said member read and; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 8th day of April, A. D, 1947.

LESLIE FRAZER,

First Assistant Commissioner of Patents. 

